Waterproof connectors that are commonly used in automobiles and the like are often exposed to harsh environments. In such environments, there is a danger of water or the like entering an interior of a connector through-wire or of dew condensation occurring inside the waterproof connector caused by temperature difference. In order to eliminate such drawbacks and to maintain the airtight state of a waterproof connector that is in a mated state, a separate sealing-type or family sealing-type sealing member is used in the waterproof connector. In general, such sealing members are made of an elastomer.
In a waterproof connector employing the family sealing-type sealing member, contact insertion openings are formed in the sealing member in positions corresponding to contact accomodating cavities formed in the interior of the waterproof connector. Incidentally, not only in the case of the waterproof connector using separate sealing-type sealing members, but also in the waterproof connector using the family sealing-type sealing member, there are cases in which empty cavities where no contacts are accommodated remain among the contact accommodating cavities. A conventionally known method used in such cases involves inserting a dummy plug into each of the contact insertion openings in order to prevent the entry of water from the contact insertion openings corresponding to the empty cavities.
FIG. 7 is a sectional view of a waterproof connector 101 in which a conventional example of a dummy plug 140 is used (see JP2004-071200A). The waterproof connector 101 shown in FIG. 7 comprises a housing 110 having a plurality of contact accommodating cavities 111. Contacts (not shown) are respectively accommodated inside the contact accommodating cavities 111. A tube member 112 that protrudes rearward is provided at the rear end (right end in FIG. 7) of the housing 110. A family sealing-type sealing member 120 for maintaining the airtight state of the waterproof connector 101 that is in a mated state is provided inside the tube member 112. A plurality of contact insertion openings 121 are formed in the sealing member 120 in positions corresponding to the contact accommodating cavities 111. A cover member 130 is attached to the tube member 112 of the housing 110, so that the sealing member 120 is prevented by the cover member 130 from slipping out to the rear. The cover member 130 is attached to the tube member 112 of the housing 110 as a result of a locking projection 113 provided on the tube member 112 of the housing 110 being locked with a locking opening 133 formed in the cover member 130. In addition, a plurality of contact insertion openings 131 are formed in the cover member 130 in positions corresponding to the respective contact accommodating cavities 111.
Furthermore, in order to prevent the entry of water from the contact insertion opening 121 corresponding to an empty cavity among the contact accommodating cavities 111, a dummy plug 140 is inserted into the contact insertion opening 121. The dummy plug 140 comprises an operating member 141 and a sealing portion 142 that extends forward from the operating member 141. The external shape of the operating member 141 is formed so as to correspond to a square-shaped contact insertion opening 131 in the cover member 130. The sealing portion 142 has a circular cylindrical shape having a diameter equivalent to the diameter of an electrical wire (not shown) connected to a contact. The diameter of an electrical wire means the outer diameter of the covering. The sealing portion 142 forms a tight seal with the inner circumference of a projecting rib 121a of the contact insertion opening 121 formed in the sealing member 120. When the dummy plug 140 is inserted into the contact insertion opening 121, the sealing portion 142 closes off the contact insertion opening 121, and the sealing portion 142 forms a tight seal with the projecting rib 121 a of the contact insertion opening 121. As a result, the airtight state of the waterproof connector 101 that is in the mated state is maintained. Accordingly, it is possible to prevent the entry of water from the contact insertion opening 121.
Moreover, locking projections 143 that restrict the rearward movement of the dummy plug 140 by entering locking grooves 132 formed in the cover member 130 are provided on the outer surfaces of the operating member 141 of the dummy plug 140. A flange 144 that restricts the forward movement of the dummy plug 140 is provided at the rear end of the operating member 141. Thus, the rearward movement of the dummy plug 140 is restricted by providing the locking projections 143 on the dummy plug 140, which increases the inner pressure of the housing 110, so that it is possible to prevent the dummy plug 140 from slipping out of the contact insertion opening 121 of the sealing member 120.
FIG. 8 is a sectional view of a waterproof connector 201 in which another conventional example of a dummy plug is used (see JP09-199219A). The waterproof connector 201 shown in FIG. 8 comprises a housing 210 having a plurality of contact accommodating cavities 211. Contacts (not shown) are respectively accommodated inside the contact accommodating cavities 211, and a housing lance 212 for performing the primary locking of a contact is provided in each of the contact accommodating cavities 211. Moreover, the contacts (not shown) are designed such the secondary locking of the contacts (not shown) are performed by a side retainer 220 that is inserted from below the housing 210. In addition, a hood member 213 that protrudes rearward is provided on the rear portion (right portion in FIG. 8) of the housing 210, and a family sealing-type sealing member 230 for maintaining the airtight state of the connector that is in the mated state is provided inside the hood member 213. A plurality of contact insertion openings 231 are formed in the sealing member 230 in positions corresponding to the contact accommodating cavities 211. A cover member 240 is attached to the hood member 213 of the housing 210 and is used to prevent the sealing member 230 from slipping out to the rear. A plurality of contact insertion openings 241 are formed in the cover member 240 in positions corresponding to the contact accommodating cavities 211.
Moreover, in order to prevent the entry of water from the contact insertion opening 231 corresponding to an empty cavity among the contact accommodating cavities 211, a dummy plug 250 is inserted into the contact insertion opening 231. The dummy plug 250 comprises an operating member 251, a sealing portion 252 that extends forward from the operating member 251, a locking member 253 that extends forward from the sealing portion 252, and a projection 254 that is provided at the tip end of the locking member 253. The sealing portion 252 is formed with a concavo-convex external shape and forms a tight seal with projecting ribs 231a of the contact insertion opening 231 formed in the sealing member 230. When the dummy plug 250 is inserted into the contact insertion opening 231, the sealing portion 252 closes off the contact insertion opening 231, and the sealing portion 252 forms a tight seal with the projecting ribs 231a of the contact insertion opening 231. As a result, the airtight state of the waterproof connector 201 that is in the mated state is maintained. Accordingly, it is possible to prevent the entry of water from the contact insertion opening 231. Furthermore, the dummy plug 250 can be prevented from becoming loose and slipping out by the projection 254 engaging with the tip end member 221 of the side retainer 220.
However, several problems have been encountered in the waterproof connectors 101, 201 that respectively use the dummy plugs 140, 250. First, in both the waterproof connectors 101, 201, the constructions are such that no consideration is given to removing the dummy plugs 140, 250 that have once been inserted into contact insertion openings 121, 231, respectively. For example, in waterproof connectors used in automobiles, there are cases in which a dummy plug that has once been inserted into a contact insertion opening is pulled out for the purpose of modifying the circuit structures or the like in vehicles.
In order to pull out the dummy plug 140 in the waterproof connector 101 shown in FIG. 7, it is necessary to perform the work of removing the cover member 130 attached to the tube member 112 of the housing 110 from the tube member 112. The engagement of the locking projection 113 with the locking opening 133 must be released to remove the cover member 130 from the tube member 112, and the working characteristics thereof are extremely poor.
Furthermore, in the waterproof connector 201 shown in FIG. 8, the work of removing the side retainer 220 from the housing 210 is required in order to pull the dummy plug 250. A special tool is required to remove the side retainer 220 from the housing 210, and the working characteristics thereof are extremely poor. Moreover, if the dummy plug 250 is pulled out in the waterproof connector 201, there is the risk of damaging the sealing member 230 when the projection 254 that is provided at the tip end of the dummy plug 250 passes through the contact insertion opening 231 in the sealing member 230. Because the sealing member 230 is a family sealing-type sealing member, if damage occurs to even one location, the entire sealing member 230 must be replaced, and there is a drawback in that all of the electrical wires (not shown) must be removed and inserted for this purpose.